from hashlib import md5
from time import time

import jwt
from flask_login import UserMixin
from werkzeug.security import generate_password_hash,check_password_hash
from app import db, app
from datetime import  datetime
from app import login

@login.user_loader
def load_user(id):
    return User.query.get(int(id))

class User(UserMixin,db.Model):
    __tablename__ = 'user'
    id = db.Column(db.Integer,primary_key= True)
    username = db.Column(db.String(64),index=True,unique=True)
    email = db.Column(db.String(120),index=True,unique=True)
    password_hash =db.Column(db.String(128))
    about_me = db.Column(db.String(140))
    last_seen = db.Column(db.DateTime, default=datetime.utcnow)
    posts = db.relationship('Post', backref='author', lazy='dynamic')

    def avatar(self,size):
        digest = md5(self.email.lower().encode('utf-8')).hexdigest()
        return 'http://www.gravatar.com/avatar/{}?d=identicon$s={}'.format(digest, size)
    def get_reset_password_token(self,expires_in=600):
        return jwt.encode(
            {'reset_password': self.id,'exp':time()+expires_in},
            app.config['SECRET_KEY'],algorithm='HS256').decode('utf-8')
    @staticmethod
    def verify_reset_password_token(token):
        try:
            id =jwt.decode(token,app.config['SECRET_KEY'],
            algorithms=['HS256'])['reset_password']
        except:
            return
        return User.query.get(id)

    def __repr__(self):
        return '<User{}>'.format(self.username)

    def set_password(self,password):
        self.password_hash =generate_password_hash(password)

    def check_password(self,password):
        return check_password_hash(self.password_hash,password)

class Post(db.Model):
    __tablename__ ='post'
    id = db.Column(db.Integer,primary_key=True)
    body =db.Column(db.String(32))
    title =db.Column(db.String(64))
    timestamp =db.Column(db.DateTime,index=True,default=datetime.utcnow())
    user_id =db.Column(db.Integer,db.ForeignKey('user.id'))

    def __repr__(self):
        return '<Post{}>'.format(self.body)
